Cartridge and a method of producing the same

ABSTRACT

A cartridge comprising a projectile and a cartridge case is formed with a neck at its forward end, and a sleeve-shaped holder for the projectile inserted into the mouth of the neck. A portion of the holder which is conically expanded by the insertion of the projectile bears against the inside of the neck of the cartridge case.

? atent 11 1 1 11 Urm States 9 1 Weyhmnller [451 ,Hy 31, 1973 4] CAETEKDEE AND A METHOD or [56] lkefierenees 11:11am

PWWUNG THE SAME UNIITED STATES PATENTS [75] Inventor: Rolf Weyhmuller, Greifensee, 1,470,591 10/1923 Behar 102/38 Switzerland 3,185,094 5/1965 Zehfeld... 102/93 11 08 72 l 2 38 [73] Asslgnee wermwgmschinenfabrik 3 235,268 3/1398 iii/ri 182/38 uel'likw-Bullfle AG, Zurkh, 2,482,132 9/1949 Studleret al 102/38 Switzerland [22] Filed; Aug, 30, 1971 Primary Examiner-Robert F. Stahl Arr -E. 1". W d1 th 1 l. 21 Appl. No.: 176,060 em 6 a 1 151mm [30] Fmelgn Apphcamm Priority Dam A cartridge comprising a projectile and a cartridge case Sept. 8, 1970 Switzerland 13361/70 is formed with a neck at its forward end and a sleeve shaped holder for the projectile inserted into the mouth [52] US. Cl 102/38, 29/ 1 3152/29/33; of the neck. A portion of the holder which is comically expanded by the insertion of the projectile bears [51] 1111. C1. F4211 31/00, F42b 13/16 against the inside of the neck of me cartridge case [58] Field oil Search 29/13; 102/38, 93

0 Claims, '7 Draw Figures PATENTED I975 3. 749.020

SHEET 1 [IF 2 Fi .I Fi .2 8 79,9 6 g 2 I4 4 Fig.3 6 8 r 3 7 I4 I5 4 ROLF WEYHMULLER, Inventor wwmwfw Attorneys PATENTEDJUL31 I915 3.749.020

SHEET 2 OF 2 g 6 5 Fig. 7

r N T I I ROLF WEYHMULLER, Inventor Attorneys CARTRIDGE AND A METHOD OF PRODUCING THE SAME BACKGROUND OF THE INVENTION The present invention relates to a cartridge comprising a projectile and a cartridge case formed with a neck at its forward end, and a sleeve-shaped holder for the projectile inserted into the mouth of the neck.

In a conventional cartridge the sleeve-shaped holder is soldered or welded into the cylindrical mouth of the cartridge case. This method of securing the holder in the cartridge case is awkward and adversely affects the production cost of the cartridge.

BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to provide a cartridge in which the securing of the holder in the cartridge case is simpler and more reliable than in known cartridges.

According to the invention there is provided a projectile and a cartridge case formed with a neck at its forward end and a sleeve-shaped holder for the projectile inserted into the mouth of the neck, in which a portion of the holder which is conically expanded by the insertion of the projectile bears against the inside of the neck of the cartridge case.

The present invention also provides a method of assembling such a cartridge wherein the previously conically converging rear end of the holder is conically expanded when the tail end of the projectile is forced into the same.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and other objects in view which will become apparent from the detailed description below, some preferred embodiments of the invention are shown in the drawing in which:

FIG. I is a side view of a cartridge case with a sleeveshaped holder in the mouth thereof shown in part sectional view;

FIG. 2 is a partial elevational view with parts in section of the arrangement showing a projectile fitted into the holder;

FIG. 3 is a partial sectional view showing the connection between the projectile and the cartridge case as in FIG. 2 at the instant the projectile is about to leave the arrangement;

FIG. 4 is an elevational view of a holder provided with holes for pressure equalization;

FIG. 5 is a similar view of a holder provided with slits for pressure equalization;

FIG. 6 is an elevational view with parts in section of an alternative embodiment of a sleeve-shaped holder in the mouth of a cartridge case; and

FIG. 7 is an elevational view with parts in section of the arrangement according to FIG. 6 with a projectile fitted therein.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. I a cartridge case I has a substantially cylindrical mouth 3 of smaller diameter than the remainder 2 of the case. The transition between the cylindrical mouth 3 and the substantially cylindrical remainder 2 of the case forms a conical neck 4. The cartridge case I contains a propellant charge 5. Inserted from the front end into the mouth of the cartridge case is a cylindrical holder 6. This holder 6 comprises a cylindrical sleeve-shaped part 7 which bears against the cylindrical interior of the mouth 3 of the cartridge. At its forward end the cylindrical holder 6 is formed with a flange 6 which projects outwards from the cylindrical sleeve-shaped part 7. The flange 6 rests on the edge of the mouth 3 and thus prevents the holder 6 from being pushed further to the rear of the cartridge. At its rear end the cylindrical sleeve-shaped portion 7 merges into a downwardly converging frusto-conical portion 9. This rearwardly tapering portion I and part of the adjoining cylindrical sleeve-shaped portion 7 are situated within the rearwardly widening neck 6 of the cartridge case I.

Referring now to FIG. 2 the cylindrical tail II of a projectile III is inserted into the cylindrical holder 6. The projectile I6 is fitted with a driving band 12 which is received into a peripheral groove 113. With the aid of this driving band I2 the projectile I6 rests firmly on the flange 8. At the rear of its tail ill the projectile I6 is further provided with a peripheral groove It. The sides 15 (FIG. 3) of the peripheral groove I6 diverge outwardly in the shape of a Vee. The tapering portion 9 of the sleeveehaped holder 6 snaps into engagement with this peripheral groove I4 after having first been expanded by the cylindrical body 16 of the projectile when this is inserted. The diameter of the body Ill) of the projectile in the region of the peripheral groove 16 exceeds the internal diameter of the undeformed tapering portion 9 at its narrowest point so that even after the tapering portion 9 has snapped into engagement with the peripheral groove 14 a forwardly adjoining part T6 of the holder 6 will still be conically expanded to make partial contact with the inside of the neck. portion 6 of the cartridge case I. The holder 6 as well as the projectile III are thus prevented from detaching themselves from the mouth of the cartridge case I. The distance of the peripheral groove I4 from the rear edge of the driving band 112 measured in the axial direction, should be chosen to suit the length of the sleeve-shaped holder 6 to prevent the projectile W from having too much axial clearance between its two abutments.

FIG. 3 shows that when the projectile III is tired by the ignition of the charge 6 the rear part of the sleeveshaped holder 6 will be inwardly curled over. This curled part lies between the conically widening part I6 and the conically tapering part 9 of the sleeve-shaped holder 6 (FIG. 2).

The sleeve-shaped holder 6 must be made of a material that is capable of being elastically expanded by the body of the projectile I6. Moreover, the sleeve-shaped holder 6 must always be provided with openings to admit of a rapid equalisation of pressures between the inside and outside of the wall of the holder 6 when the propellant charge is ignited. Otherwise the holder 6 might be blown out of the cartridge case ll.

In the embodiment of the sleeve-shaped holder 6 illustrated in FIG. 6 holes l? are provided in the rearward half of the holder 6 to ensure rapid pressure equalisation.

In FIG. 5 longitudinal slits 116 have been cut into the rear edge of the wall of the holder 6 at regular peripheral intervals. The presence of these slits I6 not only ensures an equalisation of pressures, but the number and depth of the slits also limits the holding force acting on the projectile I0 to a given maximum value, and fi nally these longitudinal slits I6 aim facilitate an elastic expansion of the conically tapering part 9 when the projectile It] is inserted into the holder and the latter snaps into engagement with the peripheral groove 14in the projectile 10.

The above-described cartridge is assembled by first inserting the sleeve-shaped holder 6 into the cartridge case 1 that has been previously filled with a propellant charge 5, and by then thrusting the projectile 10 into the holder 6 until the driving band 12 strikes the flange 8 of the holder. The conically tapering part 9- of the holder 6 engages the peripheral groove 14 in the tail ll of the projectile, whereas its conically expanded part 16 makes contact with the tapering neck 4 of the cartridge case 1. The assembly, comprising projectile l and holder 6, is therefore secured against becoming detached from the mouth of the cartridge case 1. Not until the round is tired can the considerable thrusts that develop fold back the conically tapering end 9 of the holder 6 to release the projectile 10. The forces which arise when the projectile is released are transmitted by the rear part of the holder 6 to the neck portion 4 of the cartridge case 1. Hence the wall of the cartridge case I is subjected substantially exclusively to radial forces and not to forces acting in the axial direction.

In conventional connections, comprising press fits, adhesive bonding of the projectile in the mouth of the cartridge case or crimping, the forces that arise act principally in the axial direction, tending to length with off the mouth of the case. The mouth must therefore be of suitable length to enable it to absorb these forces.

In contradistinction thereto the mouth 3 in a cartridge according to the invention can be considerably shortened and a greater charge can therefore be accommodated in a cartridge of the same overall lengthwith a consequent improvement in performance. Alternatively a shorter cartridge can achieve the same performance as a conventional cartridge.

In a preferred embodiment of the invention the cartridge case 1 is made of light metal, particularly of an aluminium alloy, and the holder 6 consists of steel. The interior of the cartridge case 1 is provided with a protective coat to prevent the highly compressed propellant gases in the region of the mouth 3 of the cartridge case 1 from eroding and partly melting the alloy, when the charge is ignited. The described novel type of connection between the projectile, the holder and the cartridge case particularly ensures that this protective coat will not be damaged.

With reference to FIGS. 6 and 7 the holder 6 has a rear portion 19 that has a thickened cross section. In the unexpanded state (FIG. 6) the external diameter of the holder 6 is cylindrical, whereas the internal diameter is reduced to form a rearwardly convergent taper. When the cylindrical projectile 10 is inserted into this holder 6 the internal diameter of the holder 6 is expanded into a cylindrical shape. Consequently the external diameter of the holder 6 in this region expands to create a divergent cone which bears against the interior of the neck portion 4 of the cartridge case 1. In this arrangement the projectile 10 is held in the holder 6 in a pure press fit. I claim:

1. A cartridge comprising:

a case having a cylindrical main body portion closed at the rear end thereof and containing a propellant charge, a cylindrical mouth portion of a diameter less than the diameter of said main body portion, and a hollow frusto-conical neck portion joining said main body portion and said mouth portion;

a holder positioned within said case and having a cylindrical sleeve portion of an outer diameter to contact the interior of said mouth portion of said case, the forward end of said sleeve portion having an annular flange extending outwardly therefrom abutting the forward edge of said mouth portion of said case, the rear end of said sleeve portion merging into a flexible rearwardly converging frustoconical portion, the length of said sleeve portion being dimensioned such that the point of juncture between said sleeve portion and said frusto-conical portion is positioned rearwardly of the juncture of said neck and mouth portions of said case when said flange abuts said edge of said mouth portion of said case; and projectile positioned in said holder in contact with the inner periphery of said sleeve portion, said projectile having adjacent the rear end thereof an annular groove the bottom edge of said frusto-conical portion fitting in said groove, said rear end of said projectile deforming said flexible frusto-conical portion of said holder outwardly into compression against the inner periphery of said neck portion of said case. 2. A cartridge as claimed in claim 1, wherein said projectile has an annular driving band fitted thereto, said driving band abutting the forward surface of said flange of said holder.

3. A cartridge as claimed in claim 1, wherein said frusto-conical portion of said holder has holes therein. 4. A cartridge as claimed in claim 1, wherein said frusto-conical portion of said holder has slits therein.

5. A process for assembling a cartridge comprising: providing a case having a cylindrical main body portion closed at the rear end thereof, a cylindrical mouth portion of a diameter less than the diameter of said main body portion, and a hollow frustoconical neck portion joining said main body portion and said mouth portion; providing a holder having a cylindrical sleeve portion merging at the rear end thereof into a flexible rearwardly converging frusto-conical portion;

inserting said holder, with said frusto-conical portion first, into said mouth portion of said case, such that the outer periphery of said sleeve portion of said holder contacts the inner periphery of said mouth portion of said case, and to a position such that the juncture of said sleeve portion and said frustoconical portion of said holder is located rearwardly of the juncture between said mouth portion and said neck portion of said case;

securing said holder against further displacement rearwardly into said case; inserting for a first distance into said holder at projectile with the outer periphery thereof contacting the inner periphery of said sleeve portion of said holder;

inserting said projectile a further distance into said holder, and by the -rear end of said projectile forcing said flexible frusto-conical portion of said holder radially outwardly into compression with the inner surface of said neck portion of said case, thereby securing said holder against forward displacement in said case; and

securing said projectile against further displacement in said holder;

6. A process as claimed in claim 5, wherein said sleeve portion of said holder has an annular flange extending outwardly from the forward end thereof, and said holder is secured against further displacement said holder is prevented by abutting said driving band against said flange of said holder.

8. A process as claimed in claim wherein said proti ad' e t e rear end thereof an annular rearwardlymto said case by abutting sald flange against Jec 1e has n th the forward edge of said mouth portion of said case.

7. A process as claimed in claim 6, wherein said projectile has an annular driving band fitted thereto, and

further displacement of said projectile rearwardly into groove, and the bottom edge of said frusto-conical portion of said holder is engaged in said annular groove when said projectile is inserted into said holder. 

1. A cartridge comprising: a case having a cylindrical main body portion closed at the rear end thereof and containing a propellant charge, a cylindrical mouth portion of a diameter less than the diameter of said main body portion, and a hollow frusto-conical neck portion joining said main body portion and said mouth portion; a holder positioned within said case and having a cylindrical sleeve portion of an outer diameter to contact the interior of said mouth portion of said case, the forward end of said sleeve portion having an annular flange extending outwardly therefrom abutting the forward edge of said mouth portion of said case, the rear end of said sleeve portion merging into a flexible rearwardly converging frusto-conical portion, the length of said sleeve portion being dimensioned such that the point of juncture between said sleeve portion and said frusto-conical portion is positioned rearwardly of the juncture of said neck and mouth portions of said case when said flange abuts said edge of said mouth portion of said case; and a projectile positioned in said holder in contact with the inner periphery of said sleeve portion, said projectile having adjacent the rear end thereof an annular groove the bottom edge of said frusto-conical portion fitting in said groove, said rear end of said projectile deforming said flexible frustoconical portion of said holder outwardly into compresSion against the inner periphery of said neck portion of said case.
 2. A cartridge as claimed in claim 1, wherein said projectile has an annular driving band fitted thereto, said driving band abutting the forward surface of said flange of said holder.
 3. A cartridge as claimed in claim 1, wherein said frusto-conical portion of said holder has holes therein.
 4. A cartridge as claimed in claim 1, wherein said frusto-conical portion of said holder has slits therein.
 5. A process for assembling a cartridge comprising: providing a case having a cylindrical main body portion closed at the rear end thereof, a cylindrical mouth portion of a diameter less than the diameter of said main body portion, and a hollow frusto-conical neck portion joining said main body portion and said mouth portion; providing a holder having a cylindrical sleeve portion merging at the rear end thereof into a flexible rearwardly converging frusto-conical portion; inserting said holder, with said frusto-conical portion first, into said mouth portion of said case, such that the outer periphery of said sleeve portion of said holder contacts the inner periphery of said mouth portion of said case, and to a position such that the juncture of said sleeve portion and said frusto-conical portion of said holder is located rearwardly of the juncture between said mouth portion and said neck portion of said case; securing said holder against further displacement rearwardly into said case; inserting for a first distance into said holder a projectile with the outer periphery thereof contacting the inner periphery of said sleeve portion of said holder; inserting said projectile a further distance into said holder, and by the rear end of said projectile forcing said flexible frusto-conical portion of said holder radially outwardly into compression with the inner surface of said neck portion of said case, thereby securing said holder against forward displacement in said case; and securing said projectile against further displacement in said holder;
 6. A process as claimed in claim 5, wherein said sleeve portion of said holder has an annular flange extending outwardly from the forward end thereof, and said holder is secured against further displacement rearwardly into said case by abutting said flange against the forward edge of said mouth portion of said case.
 7. A process as claimed in claim 6, wherein said projectile has an annular driving band fitted thereto, and further displacement of said projectile rearwardly into said holder is prevented by abutting said driving band against said flange of said holder.
 8. A process as claimed in claim 5, wherein said projectile has adjacent the rear end thereof an annular groove, and the bottom edge of said frusto-conical portion of said holder is engaged in said annular groove when said projectile is inserted into said holder. 